Abstract: A laser apparatus includes a laser oscillator; an acousto-optic modulation unit including a first acousto-optic modulator that diffracts a laser beam from the laser oscillator when a first ultrasonic wave is applied and a second acousto-optic modulator that diffracts a higher order beam output from the first acousto-optic modulator when a second ultrasonic wave is applied; and an amplifier that amplifies the laser beam from the acousto-optic modulation unit, a propagation direction of the first ultrasonic wave relative to a diffracted direction of the higher order beam emitted from the first acousto-optic modulator and a propagation direction of the second ultrasonic wave relative to a diffracted direction of a higher order beam emitted from the second acousto-optic modulator being different.

Abstract: A cleaning sponge roller is made of a polyvinyl acetal-based porous sponge having elasticity in a wet state and comprises a generally cylindrical roll body and a plurality of protrusions molded integrally on the periphery of the roll body. The cleaning sponge roller rotatingly cleans a material to be cleaned by contacting the top portions of the protrusions with the surface of the material and brushing off polishing residues found on the surface of the material. Each of the protrusions has a tapered protruding base portion extending from the periphery of the roll body, and a protruding end portion having almost the same sectional shape from the top end surface of the protruding base portion to the top portion.

Abstract: A cleaning sponge roller is made of a polyvinyl acetal-based porous sponge having elasticity in a wet state and comprises a generally cylindrical roll body and a plurality of protrusions molded integrally on the periphery of the roll body. The cleaning sponge roller rotatingly cleans a material to be cleaned by contacting the top portions of the protrusions with the surface of the material and brushing off polishing residues found on the surface of the material. Each of the protrusions has a tapered protruding base portion extending from the periphery of the roll body, and a protruding end portion having almost the same sectional shape from the top end surface of the protruding base portion to the top portion.

Abstract: A cleaning sponge roller is made of a polyvinyl acetal-based porous sponge having elasticity in a wet state and comprises a generally cylindrical roll body and a plurality of protrusions molded integrally on the periphery of the roll body. The cleaning sponge roller rotatingly cleans a material to be cleaned by contacting the top portions of the protrusions with the surface of the material and brushing off polishing residues found on the surface of the material. Each of the protrusions has a tapered protruding base portion extending from the periphery of the roll body, and a protruding end portion having almost the same sectional shape from the top end surface of the protruding base portion to the top portion.